Magento Get Logged In Customer’s Detail

Add this code any file.

if (Mage::getSingleton('customer/session')->isLoggedIn()) {

    $CustomerDetail = Mage::getSingleton('customer/session')->getCustomer();

    $FullName = $CustomerDetail->getName();

    $FirstName = $CustomerDetail->getFirstname();

    $LastName = $CustomerDetail->getLastname();

    $Email = $CustomerDetail->getEmail();

}